Abstract

Background

Exploitation of DNA-based analyses of microbial pathogens, and especially simultaneous
typing of several virulence-related genes in bacteria is becoming an important objective
of public health these days.

Results

A procedure for sample processing for a confirmative analysis of enterohemorrhagic
Escherichia coli (EHEC) on a single colony with DNA chip array was developed and is reported here.
The protocol includes application of fragmented genomic DNA from ultrasonicated colonies.
The sample processing comprises first 2.5 min of ultrasonic treatment, DNA extraction
(2×), and afterwards additional 5 min ultrasonication. Thus, the total sample preparation
time for a confirmative analysis of EHEC is nearly 10 min. Additionally, bioinformatic
revisions were performed in order to design PCR primers and array probes specific
to most conservative regions of the EHEC-associated genes. Six strains with distinct
pathogenic properties were selected for this study. At last, the EHEC chip array for
a parallel and simultaneous detection of genes etpC-stx1-stx2-eae was designed and examined. This should permit to sense all currently accessible variants
of the selected sequences in EHEC types and subtypes.

Conclusion

In order to implement the DNA chip array-based analysis for direct EHEC detection
the sample processing was established in course of this work. However, this sample
preparation mode may also be applied to other types of EHEC DNA-based sensing systems.